Prolonged Texas Drought Impacts Wildlife

AUSTIN, Texas — Despite welcome rains in late March, much of Texas remains parched by prolonged drought of historic proportions, and wildlife die-offs of whooping cranes and deer have been reported. However, experts say native wildlife evolved to bounce back from drought, and a bigger issue is how human water use is changing the equation, and how drought underscores the need for water planning and conservation.

"The current drought affecting all of Texas has reached historic proportions, with the past six months among the driest since the long-term drought of the 1950’s and 1917, the driest year on record." That sentence begins the March 11 situation report from the governor’s Drought Preparedness Council.

The council report said last December through February was the driest period on record for the east, south central, and upper coast regions. It also noted the entire state was classified as at least "Abnormally Dry" according to the United States Drought Monitor.

Continued dry range conditions could have a negative impact on wild turkey production and hunting prospects for spring turkey season, according to Texas Parks and Wildlife Department biologists. If parts of Texas remain parched, particularly the south, experts say Rio Grande turkey breeding activity and nesting effort will be greatly reduced or nonexistent. Rio Grande spring turkey hunting season runs April 4-May 17 in the North Zone, with special youth-only weekends March 28-29 and May 23-24. The South Zone season runs March 21-May 3, with youth weekends March 14-15 and May 9-10.

At TPWD’s J.D. Murphree Wildlife Management Area near Port Arthur, drought has delivered the second half of a one-two punch that started with Hurricane Ike last September.

The lack of rainfall means freshwater marshes at Murphree WMA that were inundated by Hurricane Ike are not being flushed of salt water. That lack of flushing is killing plants and damaging soil chemistry. The area’s brackish marshes are saltier than usual for this time of year, suffering the same stresses as freshwater marshes.

"Brackish marshes on the WMA and neighboring private ranch land which would normally be at or below 10 parts per thousand salinity are still up in the teens," said Michael Rezsutek, Ph.D, a TPWD wildlife biologist at Murphree WMA.

Rezsutek said little fresh water is available for use by mottled duck broods, and that will likely lead to a very low production of mottled ducks this season. Mottled ducks are the only Texas year-round resident duck, and are prized by hunters and wildlife biologists. They’ve been declining for the past 30 years due to habitat loss and other factors, so drought effects are adding stress to an already stressed population.

He also said alligators and amphibians are unable to recolonize areas inhabited before Hurricane Ike because of the salt water, and populations of these animals will likely remain depressed for the next several years.

Down the coast at the Aransas National Wildlife Refuge, drought may have contributed to the worst winter on record for the world’s only wild flock of endangered whooping cranes. After an encouraging multi-year comeback in which flock numbers grew each year, this is the first decline since 2001. Only 249 birds will return north to Canada this spring, down from 270 who arrived in Texas last fall.

Refuge expert Tom Stehn attributes whooping crane losses to poor habitat conditions on the middle Texas coast. He said low rainfall in 2008 resulted in saltier bays and fewer blue crabs, the primary food source for wintering whoopers. In addition, whoopers are further stressed when cranes must leave the bays to fly inland seeking fresh water.

In the Edwards Plateau of Central Texas, at spots like Garner State Park, there were reports of non-native axis deer dying from starvation coupled with cold weather earlier this year. TPWD wildlife biologists report range conditions are in poor shape, prickly pear is thin because of the lack of water and feral hogs are looking very thin and drawn down. Native whitetail deer still appear in decent condition but may not last long if the situation continues.

In the Trans-Pecos region of West Texas, last summer TPWD wildlife biologists observed a considerable drop in the pronghorn antelope population in portions of Jeff Davis and Presidio Counties, although overall Trans-Pecos pronghorn populations remain only slightly below the 30-year average. The specific causes are not known, but biologists believe there were several compounding factors, including how much of the affected area received no measurable rainfall from November 2007 to June 2008.

Meanwhile, this year a team of scientists is continuing work that will eventually guide decisions about how water pumping from the Edwards Aquifer in Central Texas should be restricted during critical drought periods. The science team is part of the Edwards Aquifer Recovery Implementation Program or RIP, a coalition of organizations working with the U.S. Fish and Wildlife Service to recover endangered species threatened by low spring and river flows. The RIP approach has been successfully used in other parts of the country to work out complex water use and endangered species issues. The EA RIP was created by the same 2007 legislation that raised the aquifer pumping cap during normal times, and as part of that agreement to increase the cap lawmakers required the RIP to be completed by the end of 2012. TPWD has four scientists on the team, examining flow needs of aquatic creatures and plants from Comal Springs all the way down the Guadalupe River to San Antonio Bay.

Finally, wildlife experts say individual citizens can do a lot to help manage problems caused by drought, including using drought-tolerant native plants for spring gardening. TPWD’s Texas Wildscapes habitat program for homeowners, businesses and small-acreage landowners has a wealth of information online about landscaping approaches that can save money, require less maintenance and use less water.